This invention relates to testing apparata and in particular to an apparatus that provides for an accurate and precise indication of the co-efficient of friction on a road""s surface from a gauge-reading in the apparatus which indicates the coefficient of friction of a road""s surface to rubber on a rubber tire of a moving vehicle on the road.
The highway department of the State of California, CalTrans, has used an apparatus of this kind since the 1960""s, and this apparatus is an improvement over the CalTrans apparatus. This apparatus is unique in the sense that no other device of this nature is known except the old one of CalTrans and this improvement over it.
The needs the invention addresses and satisfies in this kind of apparatus are increased dependability, accuracy, and ease of operation.
The invention is in an apparatus, stationary in operation, that provides accurate measurement of speed and control by a digital speed control in electronic control circuitry on a rotating tire through its sensor, to sense the tire speed. An accurate, precise reading of the coefficient-of-friction of a road""s surface is achieved. A mechanism trips a cocked bell-crank assembly that includes a bearing that is freed from its cocked position by an energized solenoid the action of which simultaneously drops the rotating tire upon the road surface being tested. A digital electronic control circuit manually initiated conducts the test automatically.
An object of this invention is to provide a dynamic testing reading from an apparatus in a static environment, such as standing in a stationary manner, without the need for the testing apparatus to be moving along a roadway.
Another object of the invention is to provide for an automated operation of an apparatus that tests for co-efficient of friction of a road surface.
A further object of this invention is to provide substantial savings in the cost of conducting a co-efficient-of-friction test by the apparatus of this invention.
A still further object of this invention is to provide portability for positioning at various stationary locations the apparatus and by which it is ready with ease for immediate operation in a next stationary location.
These and other objects and advantages of the invention will become more apparent upon a full and complete reading of the following description, the appended claims thereto and the accompanying drawing comprising seven (7) sheets of ten (10) FIGURES.